This cruise is our second year of oceanographic field work as part
of the Western Arctic Shelf Basin Interactions (SBI) Experiment. To
read dispatches from last year's cruise, check the 2002 website.

SBI
is a multi-year, multi-disciplinary program sponsored jointly by the
National Science Foundations Office of Polar Programs and the
High-latitude branch of the Office of Naval Research.
The overall goal is to understand how the Arctic shelves
communicate with the interior basin from a coupled
physical--biogeochemical standpoint. The premise is that this system
is in a delicate balance that could be upset by global change, which
in turn could have important ramifications. These include possible
melting of portions of the polar ice cover, changes in export of water to
the global ocean, and alteration of the food web with significant
consequences for native populations. From the physical oceanographic
perspective the goal is straightforward: understand how shelf water
is transferred, at the continental shelfbreak, to the interior basin
in order to help maintain the cold halocline of the Arctic
Ocean. This is the salty layer at mid-depth which shields the surface
ice cover from the warm deep water. If this shield is weakened, there
is more than enough heat contained in the underlying
Atlantic-origin water to start melting the ice from below.

SBI is divided into three phases:

Phase 1 (1999-2002) - Retrospective data analysis and
modeling to help define a new measurement program.

Phase 2 (2002-2004) - Data collection in the Chukchi and Beaufort Seas,
with continued regional modeling.